Skin manifestations of systemic disease.

BACKGROUND: Dermatologic complaints are a common reason for presentation to a general practitioner. In some cases, one needs to determine if the complaint may be a manifestation of a more serious underlying systemic disease.
OBJECTIVE: This article aims to highlight common dermatologic presentations where further assessment is needed to exclude an underlying systemic disease, to discuss classic cutaneous features of specific systemic diseases, and to outline rare cutaneous paraneoplastic syndromes. DISCUSSION: Skin manifestations of systemic disease are wide, varied, specific and nonspecific. Generalised pruritus and cutaneous vasculitis are more common cutaneous presentations where an underlying systemic disease may be present and will influence management. In certain chronic diseases such as connective tissue disease and chronic liver disease, there are characteristic cutaneous findings. Internal malignancies such as multiple myeloma may present with distinctive cutaneous findings, which need to be recognised to institute a search for the underlying neoplasm. The skin has the potential to provide a window into the patient and aid in the diagnosis of diseases of all organ systems.